The tadpoles of the funnel‐mouthed dendrobatids (Anura: Dendrobatidae: Colostethinae:<i>Silverstoneia</i>): external morphology, musculoskeletal anatomy, buccopharyngeal cavity, and new synapomorphies
Pedro Henrique dos Santos Dias, Marvin Anganoy‐Criollo, Marco Rada, Taran Grant
Abstract
We studied the larval morphology of the dendrobatid frog genus Silverstoneia and closely related species of Colostethinae. After describing external, buccopharyngeal, larval muscle, and chondrocranium morphology, we delimit 17 new larval characters, including the following 12 new unambiguously optimized synapomorphies of Silverstoneia: (a) medial emargination on the upper and (b) lower labia, (c) distinct gamma-shaped crest in prenarial arena, (d) postnarial papillae oblique, (e) lateral ridge papillae keel-like, (f) dermal crest on buccal floor arena, (g) additional slip of the m. subarcualis obliquus inserting on a medial aponeurosis, (h) fibers of the m. subarcualis rectus I inserting on a medial aponeurosis, (i) fibers of the rectus cervicis inserting on a medial aponeurosis, (j) complete fusion of the suprarostral corpus and alae, (k) adrostral tissue mass with cartilaginous core, and (l) basihyal free. We also identify the fusion of suprarostral corpora above the distal line as a novel larval synapomorphy for Epipedobates. Finally, we discuss the ecomorphology and convergent evolution of funnel-mouthed tadpoles, which evolved at least seven times in six families.